1. Field
The present application relates generally to layer thickness measurement, and, more particularly, to layer thickness measurement in conductive layer processing tools.
2. Description of the Related Art
Integrated circuits are generally manufactured by forming various materials, such as metals and dielectrics, on a wafer to create composite thin films and patterning the layers. It can often be useful to have an accurate measure of the thickness of a layer formed on a substrate. For example, a layer can be initially over-deposited onto the wafer to form a relatively thick layer, and a planarization process is employed to thin the layer to a desired thickness. Knowing the thickness of the layer can help control the planarization process.
Methods of determining layer thickness include in situ and ex situ techniques. Known processes each have particular advantages and disadvantages for various applications.